Understanding Water Discounts and Lye Solution in Soapmaking

One of the most common issues I run into with soapmakers is not understanding how the lye solution in soapmaking works. For instance, a soapmaker might take one of our recipes and incorrectly use the “water as a percentage of oils” option instead of the “lye concentration” option and think there is something wrong with the formula. Or misunderstand how to partially replace the water in a recipe, like the Lemon Zest & Blueberry Yogurt Recipe.

Even bigger issues crop up when a soapmaker tries to scale up and doesn’t understand the lye solution when trying to masterbatch or when they reach out for recipe help because the recipe is soft, traces too quickly, or takes a long time to cure!

Many soap calculators compound the issues by presenting the default options of calculating the water as a percentage of the oils, so newer soapmakers are missing out on this vital information!

Understanding Your Lye Solution in Soapmaking!

Let’s talk about the elephant in the room first:what’s wrong with calculating your water amount based on the oils?

Simply put, you end up with a large variety of solution strengths! Different oils need varying amount of lye of to saponify, but the amount of water won’t change based on the lye. Since the amount of water present helps determine both your speed of trace and your cure time, this can create inconsistent results from batch to batch.

For instance, if calculating your water amount based on a percentage of the oils, these two formulas are wildly different:

100% Olive Oil Soap

16 ounces of Olive Oil

2.06 ounces of Lye

38% of oils: 6.08 ounces of water

results in a 25.3% lye solution

100% Coconut Oil Soap

16 ounces of Coconut Oil

2.79 ounces of Lye

38% of oils: 6.08 ounces of water

results in a 31.42% lye solution

The olive oil soap will trace slower and cure slower than the coconut oil soap, due to the varying lye solution strength from batch to batch, even if you made the soaps on the same day! However, the coconut oil soap will saponify even faster and enter gel phase at a much higher temperature (though the gel phase will be shorter duration).

The bigger problem with this is that olive oil saponifies slower than coconut oil anyways! It would be better to have a stronger lye solution and less water for the olive oil soap (so that it doesn’t take a year to cure and an hour to trace). Since coconut oil saponifies more quickly on its own, it would be more beneficial to have a weaker lye solution and more water so the lack of water isn’t compounding the issue.

My biggest concern with calculating your water as a percentage of oils is that you might accidentally discount your water too much! If you aren’t keeping your lye in mind by calculating your water based on your lye, you could do something like this:

100% Olive Oil Soap

16 ounces of Olive Oil

2.06 ounces of Lye

15% of oils: 2.40 ounces of water

results in a 46.19% lye solution

100% Coconut Oil Soap

16 ounces of Coconut Oil

2.79 ounces of Lye

15% of oils: 2.40 ounces of water

results in a 53.72% lye solution

The coconut oil soap’s lye solution is too concentrated! Lye cannot dissolve into a solution with less liquid than its own weight. If you were to make this soap, it would be lye heavy and unevenly saponified, with free particles of lye in the bar.

In order to master water discounts and water replacements or alternative liquids, you must be able to understand your water in relation to the lye instead. The easiest way to do this is to look at your lye solution as a whole ingredient and calculate your water as a ratio of the lye.

The Most Common Lye Solutions in Soapmaking

Most early soapmaking books and recipes use a “full water” amount, which is a misnomer as there is not a maximum amount of water you can add to a soaping formula. (Yes, you could use more!)

When most recipes refer to full water, they are usually calculating a lye solution strength between 25% and 28%, which means that 25% to 28% of the solution is lye and the remainder (72% to 75%) is water.

A 25% lye solution is made of 25% lye and 75% water.

As we know, the higher the amount of water, the slower the trace (but also the longer the temperature phase during saponification). Using “full water” will give you the maximum amount of time at a workable consistency, but will also ensure a fully gelled soap in most cases (which may not be ideal!) It will also take the longest for a soap with a 25% lye solution to cure because there is a lot of water to evaporate.

The next most common lye solution strength is a 33% lye solution, which is ideal for a slightly faster curing time (less water to evaporate), reduced length of heat phases during saponification, and slightly harder bar straight out of the mold.

A strong water discount is typically referred to as a 40% lye solution. Reducing the water amount in your lye solution will help the soap get out of the mold quicker and cure faster. Compared to a soap made with a 25% lye solution, soap batches made with a 40% lye solution can cure in about half the time.

A 40% lye solution is made of 40% lye and 60% water.

Keep in mind that a soap made with a stronger lye solution like a 40% solution will trace more quickly!

The least amount of water you can use to fully dissolve lye (at optimal temperatures and conditions) is a 50% solution. Remember, this means that 50% of the solution is lye and the other 50% is water. This is considered the strongest lye solution strength and the highest water discount possible.

A 50% lye solution is made of 50% lye and 50% water.

It’s important to remember that your lye solution can be a maximum strength of 50% lye and 50% water in ideal conditions. However, if your 50% lye solution is used or stored in an environment that is too cold (less than 25° C or 77° F), the lye can precipitate out of the solution.

Using a lye solution where the lye is no longer dispersed in the liquid or water can cause uneven saponification and lye pockets. As such, I tend recommend using a weaker solution strength (40% lye solution) as the maximum water discount in most cases.

However, a 50% lye solution does become quite handy when you want to use alternative liquids. For instance, you can create a 50% lye solution with water and lye, and then add an additional liquid (such as goat’s milk) to the lye solution or oils. This will increase the water amount (slowing down trace), add additional properties, and reduce any issues with creating a lye solution with alternative liquids (freezing milk or scorching).

How to Calculate Your Water Amount for Your Lye Solution

When you calculate your formula, you usually choose your oils first, which then dictates your lye amount depending on each oils’ weight and saponification value. Then, you can determine your water amount by choosing a solution strength. A quick and easy way to do this is to multiply your lye amount by a corresponding multiplier.

Let’s say you would like to create a 50% lye solution and your oils dictate that you need 3.5 ounces of lye. You would multiply 3.5 ounces x 1 = 3.5 ounces of water. If you would like to create a 33% solution instead, you would multiply 3.5 ounces x 2 = 7 ounces of water.

If you aren’t sure what the multiplier is and don’t have the chart below handy, you can find out by doing a little math! Let’s say that you want a 25% lye solution, so you would:

If you know you need 2 ounces of lye (because your lye is determined by your oils), and want to use a 25% lye solution, you would simply multiply your lye amount by 3 to find your water amount.

2 ounces of lye x 3 = 6 ounces of water

The table below covers the full range of multipliers from a 25% solution to a 50% solution, and highlights the most commonly used concentrations:

Lye Amount

Water Multiplier

Lye Solution

Notes

Weight of Lye

x 1 = Water Amount

50% lye solution

maximum water discount

Weight of Lye

x 1.1 = Water Amount

47.6% lye solution

Weight of Lye

x 1.2 = Water Amount

45.5% lye solution

Weight of Lye

x 1.3 = Water Amount

43.5% lye solution

Weight of Lye

x 1.4 = Water Amount

41.7% lye solution

Weight of Lye

x 1.5 = Water Amount

40% lye solution

strong water discount

Weight of Lye

x 1.6 = Water Amount

38.5% lye solution

Weight of Lye

x 1.7 = Water Amount

37% lye solution

Weight of Lye

x 1.8 = Water Amount

35.7% lye solution

Weight of Lye

x 1.9 = Water Amount

34.5% lye solution

Weight of Lye

x 2 = Water Amount

33.3% lye solution

moderate water discount

Weight of Lye

x 2.1 = Water Amount

32.3% lye solution

Weight of Lye

x 2.2 = Water Amount

31.3% lye solution

Weight of Lye

x 2.3 = Water Amount

30.3% lye solution

Weight of Lye

x 2.4 = Water Amount

29.4% lye solution

Weight of Lye

x 2.5 = Water Amount

28.6% lye solution

mild water discount

Weight of Lye

x 2.6 = Water Amount

27.8% lye solution

Weight of Lye

x 2.7 = Water Amount

27% lye solution

Weight of Lye

x 2.8 = Water Amount

26.3% lye solution

Weight of Lye

x 2.9 = Water Amount

25.6% lye solution

Weight of Lye

x 3 = Water Amount

25% lye solution

no water discount

Okay, what about if I want to just figure out my water amount without all this multiplier nonsense? Can do! Take your amount of lye and your desired solution strength and plug it into this calculation:

It doesn’t matter which way you decide to conquer the beast, as long as you are calculating your water amount based on your lye!

Why It’s Important to Understand Your Lye Solution in Soapmaking

Besides being able to control trace and curing time, understanding your lye solution in soapmaking will open the doors to being able to replace some or all of your water in a formula without concerns. You’ll be able to use multiple liquids or do a partial water replacement, without having to worry about scorching lye solutions or using too little or too much water.

To find how much liquid I need for a 33% lye solution, I multiplied the amount of the lye by 2. I knew that the lye needed at least its own weight to dissolve in water (5.3 ounces). As such, I was free to use up to 5.3 ounces in avocado puree. My avocado was small, weighing in at 4 ounces, so I used a bit more water instead!

When you understand your lye solution in soapmaking, you’ll also be able to scale up your production easier with masterbatching. For instance, you could make a large amount of 33% lye solution to use in all of your recipes. If you calculated your water as a percentage of oils, you wouldn’t be able to use one lye solution in different formulas!

To dive into really understanding your lye solution strengths, give Auntie Clara’s ghost swirl a try! It will show you exactly how varying lye solution strengths affect your soap during the production process, saponification, and cure.

When it comes to my own soapmaking, I prefer 33% lye solutions in smaller batches (five pounds or less) and 40% lye solutions in larger batches (more than five pounds). Do you have a favorite lye solution strength in your soapmaking? If so, leave a comment below and tell me why! I think it’ll be interesting to see what other soapmakers use as their go-to!

Hey-ho, I'm the soapy founder of Modern Soapmaking, and I eat, breathe, and sleep soap. (Okay, I don't eat soap... that's gross.) My passion is in helping other soapmakers find their path, whether it's in the craft or as an entrepreneur. Maybe, I can help you find yours?

I prefer to work in ratios for some reason. Ever since I first started soaping I ignored the other options and worked with the ratios.

I love a ratio of 2.2:1 for my main recipe which has a fairly decent amount of hard oils, it gives a good time to work with my batter, but a newbie would find it difficult.

Soft oil heavy bars like my facial soaps are always a 1.8:1 ratio. If they’re all one colour I’ll drop it to 1.2:1.

The pure olive and coconut oil soaps are 1.1:1. Olive because I want it hard fast and coconut at 0% superfat is only used as laundry soap. I want my coconut hard within 3 hrs, so I can unmould and grate it while it isn’t a brick you could build a house with.

Kenna ~ Thank you for your fantastic lesson on Lye solutions! Super well written ~ I understand the equations now, which is awesome since I don’t enjoy math. Thank you again 🙂 My favorite ratio I now recognize to be 33 %. Shorter cure, harder soap to unmold as you described, and still allows gel if I insulate &/or soap warmer… 120+ epending on ambient temps.
Yay! Have a nice day!

This helps so much! My vegan soaps were coming out so, so, soft because I was using WAY too much water in an effort to have more time for intricate designs (can we say “soap challenge” , lol?). However, this makes so much more sense than doing it as a percent of oils! Thank you! Here’s hoping my next all vegan batch won’t need three days in the mold and to be cut with fishing line to keep from smearing colors. (It was so. So. Soft.)

Awesome post Kenna! My default is 35%, and then I tweak the lye concentration depending on the additives and EOs and how they affect the speed to trace based on previous experience with the particular recipe.

Thanks Kenna! Interesting, I would have never thought to use the water as a percentag of the oil….of course yiu’d want to manipulate the strength of your lye solution…i trued Auntie Clara’s ghost swirl…you are so right it really teaches you how different lye solutions make a big difference. It’s a fun thing to play with. Againg thanks! I love all of your posts!!!

Thanks for the informative article! I must say, you are one of the few, if not the only one that puts out informative articles like this. Most of them are general in nature and do not go into such depth. So glad I subscribed.

I do have a question on making coconut soap….I love it, love the creaminess and the feel on my skin so I want to get it right. I made a small batch several months ago but was disappointed with the result and don’t know where I went wrong. I even posted on another forum but got no insight.

Recipe as follows: 100% Coconut Oil, 33.3% Lye concentration. I placed my mold in the freezer for 3.5 hours thinking that this would prevent gel phase because I wanted a pure white soap. I unmolded about 19 hours later. The soap was pure white on the outside and somewhat soft and a bit crumbly. Once I sliced the bar, the middle had a large hard oval, just like a bar of soap that had gone through partial gel phase. I ph of the soap was around 9 and seemed fine to use.

I want to make this soap again so any insight that you can offer would be much appreciated!

Nikos,
I made another batch of coconut oil soap, 40% lye concentration. I mixed my le and oil together at around 100 degrees and poured it into the mold. I didn’t insulate or cover the mold, just left it in my laundry. It did go through gel phase, but all the way through. I unmolded it about 4.5 hours after pouring and cut it. If I waited any longer it would have been too hard to cut.
I’m happy with how it came out. Though my question is, how do I avoid gel phase, or is that impossible?

Thanks so much for this, Kenna! For years I’ve been ignoring the water box in soapcalc and I just use anywhere between 1.1 and 2.8x the lye weight. My go-to for anything swirly is 2.5, which thanks to your article I now know is a 28% lye solution. For layers and anything less intricate, I use 2x lye weight, so 33% and for olive oil it’s a good old 1.1x the lye . Thanks again! I had never learned what my proportions were in % terms and now I’ll understand this formerly foreign concept when other soapmakers talk lye solution % 😀

I don’t know what the problem is but the highest concentration I’ve attempted is a 44% solution. Failed to stay solution. I did use clean vessels and utensils as well as distilled wated. I have used a glass vessel, plastic vessel, and a silicone vessel; all similar results. I stirred the lye water continuously for 2 to 3 minutes and it cleared but not for long. When i went to add the lye water to my melted fats, there was a very thin crystalline sheet of lye on top of the water. I diluted to a 30% solution and had no problems. My lye is 97% pure so i wouldn’t think that is the problem. The first time, i thought it was just because it was too cold(40°F) but i later made it on a warm day(70°F).

As noted in the article, we tend recommend using a 40% lye solution as the maximum water discount in most cases.

That said, it is possible for flakes or a thin layer of sodium carbonate to form on top of your lye solution when it reacts with the air. And, the stronger the solution, the more noticeable the reaction. That’s not a problem.

If you have solids on the *bottom* of your container, that’s a big problem as it is likely lye that has not been held in the solution.

That’s another good article that can help people on understanding the principal theory in soap making.

As I also teach in soapmaking classes, I have seen that math is a very strange language in most of the women that are attending the seminars.
So for me it works better to speak with ratio instead of percentage when it comes to Lye Concentration. The % symbol is unknown to most students and ratio seems to be more friendly as it reminds them of cooking.

Furthermore many might not understand the very nice pictures that you share with the various lye concentrations and I have also heard a student asking me if with 40% lye concentration a recipe has more NaOH than with a 25%. Well as we can observe the pictures above without any math background, someone might understand that there is really more NaOH (pink area) in the vessel for a specific recipe. So ratio seems to be a more earthly explanation.

I also call lye the NaOH in water solution.

My most used lye concentration is 33% but I have started to like the 38-40% lately.

Keep up the very good articles that you share and I wish you a lovely new year!
🙂

Great article. Because of you I started using 33% in many of my recipes. However, your explanation of the various strengths of lye and water and their impact on the quality of a bar based on oils, etc. was a real learning curve for me. It answered a lot of questions I was having based on the type of bar and design techniques. I am going to try out Auntie Clara’s ghost swirl when I get a chance. Thanks as always for taking the time to educate and inform.

The contraction “it’s” is commonly misused. I remember looking that up a couple of times for myself when I used it incorrectly. I know what the commenters mean, but I always refrain from correcting them. I am by no means a grammar wiz and I actually appreciate when someone takes the time to politely educate or correct me. We learn through our mistakes, but I’ve found that many people don’t see it the way I do and become angry. I never know if the person doing the correcting is trying to be helpful or just rude and sarcastic. I most likely have a mistake or two here as well, but this is not the Writers Writing Right Club forum, so most people don’t care. 🙂

Great post! I first learned about manipulating water in soapmaking when I wanted to learn how to masterbatch the lye and replace some of the water with milk. I turned to Kevin Dunn’s book on scientific soapmaking which was a great read, but this post does a great job of presenting the topic quickly and in terms that are easy to understand. Thanks for taking the time to write it up!

I love your article! I would discount my lye by 5-8% and use 15 oz as my base for water in a three lb batch of soap. So this concept is new to me. But i am not clear on how to figure out how much of a lye discount i am using with your calculation. I feel that your way gives me more control on the trace factor. But in order for me to do the change over from my way to yours i need to know that discount factor. Can you help? Thanks for your web site. I have learned a lot and i have been doing soaps for over 5 years. Who said you cant teach and old dog new tricks!!

Hi ! In the avocado purée example, does that mean you add purée after trace? Is that what replacing means? Or do you add it at the same time? Also, how do you know when your soap is done curing especially if you are doing plain Jane soaps? Thanks! Love your blog!!

I primarily use a 33% lye solution, but if I have an FO that accelerates rapidly I will increase my water. I just made a Gardenia soap which is known for ricing & seizing. So, I used every trick I know. I used a 27% lye solution, 30% canola oil, and soaped at 90 degrees. This gave me time to use 2 colors & it never riced on me. Thanks for providing the lye solution chart. The correct lye solution can mean the difference between a great soap & a soap FAIL!

I’ve been using a steep water discount in all of my formulas and I haven’t had glycerin rivers since. But because of the water discount, I can’t achieve intricate swirls and designs. But if I don’t discount water at a 1.5:1 (water:lye) or lower ratio, I always get rivers. I have watched so many videos on swirling and intricate techniques, how do they have so much time to work with their batter, but not get rivers in their finished bar?

Best tutorial ever! I have been soaping awhile using 1:1 pre made lye solution, then adding extra water to 33%. I have a Lilac fragrance that wants to trace too quickly.
I needed a quick refresher on water discounting to increase water in this recipe. I had forgotten which direction to go , lower percent or higher!!
It has been awhile since I have looked at water discounting, I got it now thanks so much, love your blog!

Awesome explanation! I was wondering about the different options the soap calculators give. Now I get it and can make informed decisions for myself.
I’m working on a shaving cream soap and this stuff is important because I want to use Aloe Vera gel without eating into the lyes’ water supply!
Thank you very much for this clear and concise explanation.

Can you help clarify if you added the lye to 5.3 oz of water and then later added 5.3 oz of avocado puree? Or did you add the lye to the 5.3 oz of Avocado Puree directly? Thanks – this was a very helpful post!

I also prefer the ratios. It also depends on what type of soap I am making. CP soap gets a 1.8:1 (water/lye) ratio because I add 1oz of cream ppo after emulsification. HP soap gets 1.4:1 (water/lye) ratio because I add a few additives (cream, honey & water, yogurt and then superfat with additional oils) after the cook.

I’m trying to wrap my brain around masterbatching lye water, which I would like to do at a 50/50 ratio; however, I usually like to do a 15-20% water discount for my soaps. How would I calculate the amount of liquid/water to add back into my lye water masterbatch solution that includes a 15-20% discount for a recipe?

Would I take the total number of water called for to add back and multiply it by .15 or .20 to determine the discount? For example, if I calculate that I needed to add 6.15 oz into my masterbatched lye water amount for a full water recipe, would I then multiply 6.15 X .20 to give me a 20% discount amount, which would be 4.92 oz. to add to the masterbatched lye water amount?

I do but don’t understand water discounts. I really, really sucked at math and still do to this day. Been over yrs since I graduated. So that should tell you how much I hated math :)….So if one wants to add cream and water to a recipe. How does one calculate that. I am getting so frustrated at this “soap making” gig that I don’t even want to attempt to make soap anymore. Please help!!!! Thank you 🙂

have you ever tried whipped soap by pre mixing the lye and water solution and letting it cool then you whip your oils together and add in the lye solution! you have 30 minutes plus of play time since there is no heat issue to deal with and it makes Beautiful soap.

On a recipe that called for 6.08 ounces of water and 2.25 ounces of lye, I confused it with 6.80 ounces of water instead. How will that affect my recipe?
My recipe:
4 oz Olive Oil
4.8 oz Tallow (Beef)
2.4 oz Shea butter
4 oz Coconut Oil
0.8 oz Castor Oil

Hey, Cheryl,
So, instead of adding 6.08 ounces of water to your batch, you added 6.8 ounces? Well, you lucked out, because water amount is probably the most flexible part of a soap recipe. Your soap may stay softer longer, and it may have some shrinkage, but, as long as everything else was on point, you should still have soap!

That said, be sure to check and recheck your ingredients and amounts for every recipe. (And yes, we recommend a literal check sheet so you can tick of ingredients as you add them!) Had your mistake been with lye weight rather than water, that would be a bigger issue!

Hello there!
I have a question: what happens if I calculate the water and the lye according to the oils (with 25% lye to water) and then add some more water (without adding more lye or oils) ? So in this case actualy I don’t have lye discount, but I have excess water.

Is more simply expressed as 100/25 – 1, Since percentages are really just parts per 100, you’re turning it into a ratio i.e. how many parts of water to lye. In the 25% example, there are 4 total parts (100/25), of which one is the lye, which is why you subtract 1. A 25% solution is made with a ratio of 3:1, lye:water. Essentially, the purpose of the formula is to turn a percentage into a ratio, so it’s confusing and needlessly complex to subtract a percentage first. The percentage you’re subtracting is just the ‘part’ lye before you’ve properly converted to a ratio.

I’m finding it difficult to get long enough to work my soap as it is tracing so quickly. My recipe seems right but it traces in 30seconds even at room temperature as well as 100 degrees F. It sets perfectly and is easy to unmould which I love but hate that I don’t have time to even add a fragrance or colour as it’s so thick.

7oz olive oil
7oz Coconut oil
7oz Palm oil
1oz Castor oil
3.1 Caustic soda
8 oz water
I usually exchange the water for 3.1oz water and 4.9 goats milk.
Could you help me as I would love to get this recipe right.

Hey, Sola,
You can totally use SoapCalc to save you time on the calculations. Knowing how different lye solution strengths influence your soap will be helpful whether you do the figures or leave it up to the calculator.

Love this post! Kenna, you are the QUEEN OF DETAILS!!! I love that because I’m a detail person too. I have one question you may or may not be able to answer. When I entered the same exact recipe in Brambleberry’s lye calculator and SoapCalc’s, I got two different lye amounts. Why would that be? Same oils and weight of oils, same superfat percentage and they both gave me the same water amount. It’s kind of scary to not know how much lye to use. It is a difference of 2.55 grams in a recipe using 1531 grams of oil.

Hey, Maralee,
Each type of oil actually has a range of possible SAP values. Coconut oil has a SAP range of 250-265 for example. So, the batch of coconut oil you buy today may actually have a different SAP value on the spec sheet than the lot you bought 3 months ago. However, refiguring your recipe each time you switch to a new batch of oil would be super time-consuming.

So, lye calculators are programmed with an average SAP value for each oil, but depending on the oils sampled, the average they come up with might be slightly different for each calculator. Meaning the same recipe variables will call for slightly different amounts of lye.

Another issue that might come into play is what percentage of lye purity the calculator is set for. Food grade lye has a slightly higher percent of purity than technical grade lye. If the calculator you are using doesn’t disclose the percentage of purity they are using to calculate, you may want to ask. In my experience, most use tech grade, since it is most widely marketed to soapers.

That said, both of these issues make a rather small difference in the end product. The 2.55 grams, more or less in your own recipe is not going to make or break it.

No.It has a big impact on your receipe.It happens to me the same.I used soap calc and i made exactly as it said there.My soap was heavy lye in the end.I wondered why???i used the bramberry calc and surprise!!! THE AMMOUNT OF LYE WAS DECREASED WITH 4 GRAMS FOR THE SAME RECEIPE!!! THE SAME OILS!
I am afraid to use soap calc now!
For the second soap i used the same receipe,same oils with bramberry calc and my soap is not heavy lye!
It makes a huge difference what soap calc you use!
An extra lye can create a bad soap.
Now i am using soap calc for the extra information they give,but i use the lye ammount bramberry gives!
So,when I make soap I have 2 sheets of paper in front of my eyes!
Yes.Some grams of extra lye makes a huge difference.Example my heavy soap using soap calc.
People must know.

Hey, Adriana,
Despite the way we talk about types of oil having a SAP value, in actuality, every batch of any oil will have it’s own SAP value. There isn’t usually a ton of variation, but oils come from plants and animals so, they are affected by weather, region, diet, etc. So, calculator creators take average figures and use those to calculate the SAP of your oil blend. And some even allow user entered info. That’s why values can vary. Usually, an average superfat provides plenty of buffer.

I’ve used Soap Calc for about 20 years and consider it a great tool. But, there is no harm in double checking. Whether four grams of lye is a big difference depends on your recipe size. So, I would also make sure you check out that batch record and make sure your scale was recently calibrated if your soap tested lye heavy, just to be sure there isn’t something else going on.

It was back in 2016-2017, when you still offered your formulating class that I first fell in love with this explanation! I love that it’s on the website and I can easily pull it up when needed. I still refer other soap makers to it whenever the questions about water discount and lye solutions come up. I normally use anywhere between a 36% and 38% lye-solution when making my Cold Process soaps, depending on how my fragrances tend to behave lower % with accelerators and higher % with well-behaving).

But this week this article came in particularly handy. I missed a deadline I needed to meet to make CP bars for an upcoming Bridal Shower next weekend. I decided to do the bars using the Countertop Fluid Hot Process Method so they would be done on time. Using the chart, I did an initial 40% lye solution. I didn’t want to go higher than that due to the danger of increased volcano activity. After initially blending and barely getting to applesauce stage, I added more hot distilled water to bring the solution down to a 38%. The reason was to get the “cook” going faster. For me this worked out really well, as in within a minute or two! (PS: I PH test my bars with an Apera meter and cook it to a 9.5-ish). After getting down to 180*F post-cook, I was able to add all my additives and FO’s without burning anything off, AND POUR, not scoop, my soap into the mold. These bars turned out very smooth, not rustic, like the bride-to-be wanted them. 🙂

38% lye solution was desired to unmold the bars and get them cured out faster (using a fan and dehumidifier) before I package them. 40% lye solution though, with the countertop fluid hot process method, was intense to watch how fast everything came together though! Amazing the difference you see in that 2% during a hot process in comparison to cold process!

[…] * I know that this is a steep water discount. I like to do this so that my soaps harden quickly and cure quickly. Please feel free to adjust this recipe for more water: a 33% solution would use 13.2 ounces of water total. If you need help understanding lye solutions in soapmaking, this article will help. […]

Footer

Ready to get your swagger on?

Get your hands on my weekly value-filled emails and snag my Soap Biz Success Plan as a bonus. You'll be struttin' your biz smarts all over the place in no time. (Say goodbye to being stuck in a rut; no more wasting time, money, and effort, superstar!)